Composition and method of treating fabrics



United States Patent "ice 3,268,465 COMPOSITION AND METHOD OF TREATINGFABRICS John W. Gilkey and Richard W. Alsgaard, Midland, Mich.,assignors to Dow Corning Corporation, Midland, Mich., a corporation ofMichigan No Drawing. Filed May 15, 1961, Ser. No. 109,868 11 Claims.(Cl. 260-291) This invention relates to a mixture of siloxanes suitablefor rendering fabrics water repellent and is a continuation-in-part ofapplicants copending application Serial No. 10,577, filed February 24,1960, now abandoned, which is in turn a continuation-in-part ofapplicants copending application Serial No. 662,336, filed May 29, 1957,now abandoned.

Organosiloxanes, particularly those containing methyl groups andhydrogen atoms bonded to the silicon have become widely used as atreatment for textiles, These siloxanes impart many desirable propertiesto the textile such as water repellency, stain resistance, improvedhandling, improved abrasion resistance and improved sewability. Thesiloxanes have been used on all types of fabrics. However, the use ofsuch siloxanes on cotton fabrics has been held back by the fact thatheretofore employed siloxane treatments of cotton did not give durablewater repellency with respect to laundering. In general, cotton treatedwith heretofore employed siloxanes has an initial spray rating of 100,but this spray rating generally drops to zero after from one to twowashings at 160 F. Because of this feature organosiloxanes have not beenwidely employed on cotton except for expensive cotton fabrics which arenormally dry cleaned.

As a result of this a large potential use of organosiloxanes has beenleft untouched. Since washable cottons represent the largest singletextile now in use, it would be highly desirable to have a siloxanematerial which would be durable to laundering and which would have allthe other desirable features of the heretofore employed siloxanes.

It is the object of this invention to provide a novel composition ofmatter capable of imparting durable water repellency to cellulosicfabrics. Another object is to provide a composition which decreases theshrinkage of wool. Another object is to provide a composition which isuseful on all types of organic fabrics. Other objects and advantageswill be apparent from the following description.

This invention relates to a composition of matter comprising a mixtureof (1) from 1 to 40 percent inclusive by weight of a siloxane of theformula in which 0 has a value from 0 to 3 inclusive, R is an aliphatichydrocarbon radical of less than 4 carbon atoms, a has a value from 1 to2 inclusive, R is a divalent or trivalent saturated aliphatic orcycloaliphatic hydrocarbon radical of at least two carbon atoms, Y is amonovalent hydrocarbon radical or a fluorinated monovalent hydrocarbonradical =and m has a value from 0 to 2 inclusive,

*A spray rating of 100 shows that the fabric is completely waterrepellent. A spray rating of 50 means that the entire surface of thefabric is wet but no water has soaked through. .3 spgraylrating of zeromeans that the water soaks through e a r e.

which siloxane may contain up to mol percent of a copolymerized siloxaneof the formula in which Z is a monovalent hydrocarbon radical or afluorinated monovalent hydrocarbon radical and b has an average valuefrom 1 to 3 inclusive and (2) from 60 to 99 percent by weight of asiloxane having an average of from 1 to 3 substituents of the groupmonovalent hydrocarbon radicals, halogenated monovalent hydrocarbonradicals and hydrogen atoms, per silicon, in siloxane (2) there being anaverage of at least one of said organic radicals per silicon, siloxanes(1) and (2) being in such proportion that in the total mixture there isat least .7 percent by weight of (A).

Siloxanes (1), both with and without copolymerized siloxane (B), areprepared in accordance with the methods set forth in U.S. Patent No.2,838,423, issued June 10, 1958, the disclosure of which is herebyincorporated in this application by reference.

Briefly, siloxane '(A) is prepared by reacting a siloxane amide of theunit formula Elf... rnNoc)..1 .'sio

in which a, R, Y and m are asabove defined with formaldehyde and ahydrochloride of pyridine or an alkylated or alkenylated pyridine. Thereaction is best carried out in the presence of pyridine or the definedpyridine derivatives as a solvent. These products are generally viscouswater-soluble materials.

When siloxane (1) contains copolymerized (B) the copolymers can be madeby any of the methods described in US Patent No. 2,838,423. Briefly, thebest method of this preparation comprises copolymerizing a chlorosilaneof the formula in which R" is an 'alkyl radical, with a chlorosilane ofthe formula Z SiCl in the conventional manner and thereafter bombing theester copolyrner with ammonia to produce the corresponding siloxaneamide. This copolymer is then reacted with formaldehyde and a pyridinehydrochloride as described above.

Siloxane esters of the type which are suitable as starting materials forthe compounds of this invention are described in US. Patent 2,723,987and in the copending application of Leo H. Sommer, Serial No. 522,826,filed July 18, 1955, now abandoned. For the purpose of this inventionsiloxane (2) can be any of the standard siloxanes now employed inrendering fabrics water repellent. The best water repellency is obtainedwhen siloxane (2) contains a substantial portion ofmethylhydrogensiloxane. However, any siloxane having an average of atleast 1 monovalent hydrocarbon radical or halogenated monovalenthydrocarbon radical per silicon atom can be employed in this invention.

Siloxane (2) can be a single homopolymeric siloxane or a mixture of twoor more homopolymeric siloxanes. It can be a single copolymer of two ormore siloxanes or a mixture of two or more of such copolymers and it canbe a mixture of homopolymeric and copolymeric siloxanes.

.repellency in the shortest time.

trifluorovinylmethylsiloxane, bis-trifiuoropropylsiloxane,chloromethylmethylsiloxane, 2,4 dichlorophenylsiloxane,

a,a,a-trifluorotolylsiloxane, octafiuorocyclopentylsiloxane,

monomethylsiloxane and monooctadecylsiloxane. Siloxane (2) can alsocontain some copolymerized SiO HSiO and H SiO units.

The compositions of this invention are prepared by merely mixingsiloxanes 1) and (2). These mixtures can then be applied to the fabricby any suitable means. For example, they may be employed in the form ofsolutions or emulsions. After application of the siloxane mixture to thefabric the fabric is then heated in order to fix the siloxane and todevelop the maximum water The precise degree and extent of heatingdepends on the fabric employed and the type of siloxane mixture. Ingeneral, heating times varying from 1 minute to minutes and temperaturesranging from 110 to 350 F. are suitable. After the fabric has been sotreated it is ready for use and the water repellency is highly durableto laundering especially on cellulosic fabrics.

For the purpose of this invention siloxanes (1) and (2) can beemulsified by any of the conventional techniques for preparing siloxaneemulsions employing any of the conventional emulsifying agents.

The composition of this invention is applicable to any kind of organicfabric such as cotton, viscose, acetate, linen, silk, wool,polyacrylonitrile fibers, polyester fibers and vinyl chloride-vinylidenechloride fibers.

The amount of siloxane applied to the fabric is not critical although ingeneral it is desirable to have at least .5 percent by weight siloxane.For practical application from 1 to 5 percent siloxane is desirablealthough more or less may be employed if desired.

The treatment of textiles with the compositions of this invention can becarried out in one step or two steps. That is, a mixture of siloxanes 1)and (2) may be applied to the fabric in any suitable fashion.Alternatively, the fabric may be first treated with siloxane 1) andsubsequently with siloxane (2). It is desirable, but not essential, thatthe fabric be cured after each step. Alternatively the fabric may betreated first with siloxane (2) and then treated with siloxane (I Insiloxane (1) (A) employed in this invention R can be any divalentsaturated aliphatic hydrocarbon radical of at least 2 carbon atoms suchas ethylene, propylene, butylene, or octadecylene, or any trivalentsaturated =hydrocarbon radical of at least 2 carbon atoms such as and orany cyclic divalent aliphatic hydrocarbon radical such as cyclohexylene,cyclopentylene, or methylcyclohexenylene and and any trivalentcycloaliphatic saturated hydrocarbon radical such as S t CH. and L0H.

Y can be any monovalent hydrocarbon radical such as alkyl radicals suchas methyl, ethyl, butyl and octadecyl; any alkenyl radical such asvinyl, allyl, and hexenyl; any

cycloaliphatic hydrocarbon radicals such as cyclopentyl, cyclohexyl andcyclohexenyl; any alkaryl hydrocarbon radical such as benzyl andfi-phenylethyl and any aryl hydrocarbon radical such as phenyl, tolyl,xenyl and naphthyl. Y can also be any fiuorinated hydrocarbon radicalsuch as tritiuorovinyl, tetrafiuoroethyl, 3,3,3-trifluoropropyl,decafluorocyclohexyl, 0L,Ot,0L-l'.l'lfill0lOtOlYl and C F CH CH R inthis invention can be methyl, ethyl, propyl, vinyl or allyl.

In component (B) of siloxane 1) employed in this invention Z can be anymonovalent hydrocarbon radical or any fiuorinated monovalent hydrocarbonradical. Thus specific examples of siloxane (B) are dimethylsiloxane,ethylmethylsiloxane, octadecylmethylsiloxane, divinylsiloxane,allylrnethylsiloxane, hexenylmethylsiloxane, monoethylsiloxane,diphenylmethylsiloxane, monophenylsiloxane, xenylrnethylsiloxane,naphthylmethylsiloxane,

trifluorovinylmethylsiloxane, 1,1,1 trifluoropropylsiloxane, bistrifluoropropylsiloxane, octafiuorocyclohexylsiloxane, a,a,utrifluorotolylsiloxane and monooctadecylsiloxane. If desired, the (B)component of siloxane (1) can contain two or more different types ofsiloxane units. The (B) component can also contain some SiO units.

In general, siloxanes (1) which contain at least 30 mol percent of the(A) component are water soluble. These water soluble components can beadded without further modification to an emulsion of siloxane (2).Preferably these emulsions are diluted with water until they containfrom 1 to 5 percent by Weight total siloxanes (1) and (2). The diluteemulsion is then employed to impregnate the fabric.

The mixture of siloxanes (1) and (2) operate well as a water repellenttreatment for fabric. If desired, however, an additional curing orfixing agent may be added to the siloxane mixture. Typical catalysts aredibutyltindiacetate, lead Z-ethylhexoate, zinc hexoate,dibutyltindilaurate and other metal salts of carboxylic acids. Theseadditional catalysts can also be used when (1) and (2) are appliedseparately to the fabric. In this case the added catalyst is generallyadded to (2) before application.

The compositions of this invention can be employed on fabrics with othertypes of resins which are normally employed on organic fabrics forspecific purposes such as imparting crease resistance and the like.Specific examples of such resins are melamine formaldehyde resins andurea formaldehyde resins.

The compositions may also contain other additives which are employed onfabrics for the purpose of decreasing slip of the fibers or impartingsoil resistance. Agents commonly used for these purposes are colloidalsilicas. It should be understood that these additional materials can beapplied to the fabric either simultaneously with, before, or aftertreatment with the siloxanes of this invention.

The following examples are illustrative only and should not be construedas limiting the invention which is properly delineated in the appendedclaims.

Example 1 This example shows the contrast between the compositions ofthis invention and previous commercial silicone treatments with respectto durability on cotton.

The fabric was removed from the solution, pressed between rolls and thencured 3 minutes at 300 F. The fabric was then dipped into an emulsioncontaining 3 percent by weight of (2) a mixture of 40 percent by weightof a dimethylpolysiloxane fluid containing SiOH groups and 60 percent byweight of a trimethyl endblocked methylhydrogenpolysiloxane fluid, whichemulsion contained a small amount of zinc octoate anddibutyltindiacetate as a catalyst. The fabric was then removed from theemulsion, dried and cured by heating minutes at 300 F. The spray ratingof each sample was then determined and each sample was then subjected tothe laundering schedules shown below. In each washing Ivory soap wasused. After the designated number of washings the spray rating was againdetermined as shown in the table.

By contrast cotton treated with siloxane mixture (2) alone underidentical conditions gave a zero spray rating after five washings underany of the above conditions.

Example 2 Siloxane (1) of Example 1 was added to an emulsion of siloxane(2) of Example 1 in varying amounts so that the percent by weightsiloxane (1) based upon the combined weights of (l) and (2) in theemulsion were as shown in the table below. Samples of cotton fabric weredipped into each of these emulsions and the samples were then dried andcured minutes at 250 F. The percent by weight gain of the sample wasthen determined and the initial spray rating determined. Each sample wasthen washed five times at 160 F. with Ivory soap and the spray ratingwas again determined. The results are recorded in the table below.

This example shows the effectiveness of the treatment of this inventionon various types of fabrics. Each of the fabrics shown below were dippedinto an emulsion containing 2.4 percent by weight of a mixture of 40percent by weight of a trimethyl endblocked dimethylsiloxane fluid and60 percent by weight of a trimethyl endblocked methylhydrogensiloxanefluid and .3 percent by weight of a copolymer of 34 rnol percentdimethylsiloxane and 66 rnol percent 6 Each sample was then removed fromthe emulsion, dried and cured by heating at 300 F. for 1) minutes. Theinitial spray rating was determined and each sample was then washed 5times at 160 F. with Ivory soap. The spray rating after these 5 washingswas also determined.

Initial spray Spray rating rating after 5 Fabric washings Cotton 70Viscose 80 Acetate 100 70 50% Viscose, 50% Acetate 100 80 Nylon 100 80Wool 100 *80 *The wool sample was dry cleaned 5 times rather thanwashed.

Example 4 Cotton fabrics were treated with each of the siloxane sampleshaving the compositions shown below by dipping the fabric into thesiloxane emulsion samples and thereafter drying the fabric and curingfor 10 minutes at 350 F. The initial spray rating was determined andeach fabric was then washed at F. with Ivory soap for the number oftimes indicated and the spray rating was again determined. These resultsare shown in the table below. The sample compositions are:

1 g. of

35.6 g. of the siloxane emulsion of sample 1 7.1 g. of the catalystemulsion of sample 1 .75 g. of

01+N05H5CHgNHQCCmHgoSlO These ingredients were diluted with water to atotal weight of 500 g.

III.

4.5 g. of the siloxane emulsion of sample 1 .9 g. of the catalystemulsion of sample 1 .2 g. of a copolymer of 50.3 mol percent (13H; (3H-Cl+NC5H5CI-IZNHOCCHCHzSiO and 49.7 mol percent3,3,B-trifluoropropylmethyl siloxane This mixture was diluted with waterto a total of 74.4 g.

A mixture of 32 g. of a 506 cs. viscosity diphenylmethyl endblockedpropylmethylsiloxane fluid 48 g. of a trimethyl endblockedmethylhydrogenpolysiloxane 20 g. of a mixture of 60% toluene and 40%perchloroethylene was emulsified with 98 g. of water using 17.4 g. of amixture of 10.8 percent by weight polyvinyl alcohol, .7 percent byweight sodium lauryl sulfate and 88.5 percent water as the emulsifyingagent.

36.5 g. of this emulsion were mixed with 7.1 g. of the catalyst emulsionof sample 1 and .75 g. of a copolymer of 36.5 mol percentdimethylsiloxane and 63.5 mol percent of the amidomethyl siloxane (3HCPI; -C1+NC H CH2NHO CCHCHzSiO The total mixture was then diluted to 500g. with water.

36.5 g. of a 40% aqueous emulsion of a trimethyl endblockedmethylhydrogenpolysiloxane fluid 7.1 g. of the catalyst emulsion ofsample 1 .75 g. of the amidornethyl copolymer of sample 4 The mixturewas diluted to 500 g. with water.

47.5 g. of a 30% emulsion of a hydroxyl endblocked dimethylpolysiloxanefluid of 1000 cs. viscosity 9.5 g. of the catalyst emulsion of sample 1.75 g. of the amidomethyl copolymer of sample 4 This mixture was dilutedto 500 g. with water.

VII.

47.5 g. of a 30% emulsion of a 1,000 cs. trimethyl endblockeddimethylsiloxane fluid 9.5 g. of the catalyst emulsion of sample 1 .75g. of the amidornethyl copolymer of sample 4 This mixture was diluted to500 g. with water.

A siloxane emulsion was prepared containing 40 percent by weig-ht of amixture of 75 percent by weight of a hydroxyl endblockeddimethylpolysiloxane of 12,500 cs. viscosity and 25 percent by weight ofa trimethyl endblocked met-hylhydrogenpolysiloxane. To 5 parts by weightof this emulsion was added 1 part by weight of the catalyst emulsion ofsample 1 of Example 4 and sufficient of (1) a copolymer of 68 molpercent and 32 mol percent dimethylsiloxane, that (l) amounted topercent by Weight of the total siloxane in the emulsion.

This emulsion was diluted with water to a concentration of about 5percent by weight total siloxane and applied to wool fabric. The fabricwas then dried and cured minutes at 257 F. The total percent by weightpickup was 4 percent. The fabric was then washed 5 times with the waterat 140 F. using Ivory soap. The area shrinkage was 21.1 percent.

By contrast a sample of the same Wool which had not been treated withany siloxane had an area shrinkage of 44.8 percent and a sample of woolwhich was treated with the emulsion that contained no siloxane (1) (butwas otherwise identical) had an area shrinkage of 32.8 percent.

Example 6 Results equivalent to those of Example 1 are obtained when acopolymer of 50 mol percent dimethylsiloxane and 50 mol percent A E fCHzNHOCCHCHgSiO c1 is substituted for siloxane (1) of that example.

Example 7 Improved resistance to laundering is obtained when thefollowing siloxanes are mixed with the emulsion of siloxane (2) ofExample 1 in amount so that they are present in amount of 5 percent byweight based on the weight of siloxane (2), and the emulsion is thenapplied to cotton fabric and cured 10 minutes at 300 F.

armcnzwnmnooOsw H3C\N/ CH3 CH3 3 01 OHzNHGOOOHCHsSiO GH=C a CH CH3 I lOHzNHOCOHOHzSiO Example 8 Improved laundering resistance is obtainedwhen the following copolymers are mixed with the emulsion of siloxane(2) of Example 1 in amount such that the amidemethyl siloxane units inthe copolymers make up 5 percent by weight of the total siloxane in theemulsion and the emulsion is then applied to cotton fabric and cured 10minutes at 300 F.

COMPOSITION OF COPOLYMER IN MOL PERCENT 50(05115) (CH3) S10 iH5) s)S1O25 CHNC6H5CH2NHOOCHCH2S1O 0 H3 CH3 (2) 10C HgCa lg i 1.5

20 C H 7 i0 C H 10C aHuS iO C 4 9) 2Si 0 CH CH 50 'CPN 05115 C HzNH O CJHGHQS i O Example 9 Improved laundering resistance is obtained whensiloxane (1) of Example 1 is added .to an emulsion of the followingsiloxanes in amount so that there is 5 percent by weight of (1) based onthe total weight of siloxanes in the emulsion, together with 20 percentby weight based on the weight of the siloxanes infra, of a mixture of 40percent by weight triethanol amine titanate and 10 percent by weightzinc acetate, and the resulting emulsion is applied to cotton fabric andcured 10 minutes at 300 F.

(C F CH CH SiO Copolymers in mol percent of (3) 10(C2H (CHs)SiO1QC5H11SiOL5 IOSiOz 70(C,H9)2sio A mixture of 50 percent by weight of acopolymer of 10CH C H SiO lCF C H SiO and 50% by weight (C H )HSiOExample 10 Cotton was saturated with an aqueous solution of 0.9 percentby weight of a copolymer of 55 mol percent dimethylsiloxane and 45 molpercent (llHa ([lHs c1+Nc5H5oH NHoCCHcH si0 squeezed to an 80 percentwet pickup and then heated 3 minutes at 350 F. The treated cotton wasthen saturated with a 3.6 percent by Weight solution of inmethylisobutyl ketone. The ketone solution contained .11 percent byweight of a curing catalyst of the formula H NCH CH NH(CH Si(OCH and .28percent by weight stannous octoate. The cotton was then air dried andcured minutes at 250 F.

The resulting cloth had a spray rating of 100 and has good oilrepellency. The spray rating was 80 after one washing at 160 F.

That which is claimed is:

1. A method which comprises applying to an organic fabric a dispersionin a liquid carrier of (1) a siloxane of the formula from 1 to 18inclusive carbon atoms and is selected from the group consisting ofmonovalent hydrocarbon radicals and fluorinated monovalent hydrocarbonradicals and m has an average value from 0 to 2 inclusive in which (A)contains up to mol percent copolymerized siloxane of the formula inwhich Z contains from 1 to 18 inclusive carbon atoms and is selectedfrom the group consisting of monovalent hydrocarbon radicals andfluorinated monovalent hydrocarbon radicals and b has an average valuefrom 1 to 3 inclusive and a dispersion in a liquid carrier of (2) anorganosiloxane having an average of from 1 to 3 inclusive substit'uentsper silicon atom, said substituents being selected from the groupconsisting of hydrogen atoms, monovalent hydrocarbon radicals of from 1to 18 inclusive carbon atoms and halogenated monovalent hydrocarbonradicals of from 1 to 18 inclusive carbon atoms and there being anaverage of at least one of said organic radicals per silicon, in such amanner that the weight ratios of the siloxane shall range from 1 to 40percent by weight of (1) and from 60 to 99 percent by weight of (2), andsaid siloxanes being in such proportion that at least .7 percent byweight of the total of siloxanes (1) and (2) on the fabric is (A) andheat curing the siloxanes.

2. The method in accordance with claim 1 wherein the fabric is acellulosic fabric.

3. A method which comprises applying to an organic fabric a dispersionin a liquid carrier of (1) from 1 to 40 percent by weight of a siloxaneof the formula which contains up to 90 mol percent (B) copolymerizeddimethylsiloxane and a dispersion in a liquid carrier of (2) from 60 to99 percent by weight of a mixture of methylhydrogensiloxane anddimethylsiloxane in such a manner that at least .7 percent by weight ofthe total siloxanes (1) and (2) on the fabric is siloxane (A) and heatcuring the siloxanes.

4. The method in accordance with claim 3 wherein the fabric is acellulosic fabric.

5. A composition of matter comprising a mixture of (1) from 1 .to 40percent by weight inclusive of a siloxane of the formula A) Ru in whichR is an aliphatic hydrocarbon radical of less than 4 carbon atoms, c hasa value from 0 to 3 inclusive, R is selected from the group consistingof divalent and trivalent saturated aliphatic radicals of from 2 to 18inclusive carbon atoms and divalent and trivalent saturatedcycloaliphatic hydrocarbon radicals of no more than 18 carbon atoms, ahas a value from 1 to 2 inclusive, Y contains from 1 to 18 inclusivecarbon atoms and is selected from the group consisting of monovalenthydrocarbon radicals and fluorinated monovalent hydrocarbon radicals andin has an average value from 0 to 2 inclusive which siloxane contains upto 90 mol percent of (B) a copolymerized siloxane of the formula Z SiOin which Z contains from 1 to 18 inclusive carbon atoms and is selectedfrom the group consisting of monovalent hydrocarbon radicals andfluorinated monovalent hydrocarbon radicals and b has an average valuefrom 1 to 3 inclusive and (2) from 60 to 99 percent by weight inclusiveof a siloxane having an average of from 1 to 3 substituents per siliconatom, said substituents being selected from the group consisting ofhydrogen atoms, monovalent hydrocarbon radicals of from 1 to 18inclusive carbon atoms and halogenated monovalent hydrocarbon radicalsof from 1 to 18 inclusive carbon atoms, in said siloxane (2) there beingan average of at least one of said organic radicals per silicon, theproportions of (i) and (2) in said mixture being such that in the totalweight of (l) and (2) there is at least .7 percent by weight of siloxane(A).

6. A composition of matter comprising a mixture of (1) from 1 to 40percent by Weight inclusive of a siloxane of the formula CH3 on;

which contains up to 90 mol percent (B) copolymerized dimethylsiloxaneand (2) from 60 to 99 percent by weight inclusive of a mixture ofmethyl-hydrogensiloxane and dimethylsiloxane, in said mixture theproportions of (1) and (2) being such that there is at least .7 percentby weight of siloxane (A) based on the total weight of (1) and (2).

7. An article of manufacture comprising a fabric having applied theretothe composition of claim 5.

8. An article of manufacture comprising a fabric having applied theretothe composition of claim 6.

9. A method which comprises applying to an organic fabric a dispersionin a liquid carrier of (1) from 1 to 40 percent by weight of a siloxaneof the formula (A) CH3 CH3 C1+NCsHaGHzNHO G lHCHzs iO which contains upto 90 mol percent (B) copolymerized dimethylsiloxane and a dispersion ina liquid carrier of (2) from 60 to 99 percent by weight of a5,5,5,4,4,3,3- heptafiuoropentylsiloxane in which any remaining organicgroups attached to the silicon are methyl, in such a man- CH CH whichcontains up to 90 mol percent (B) copolymerized dirnethylsiloxane and(2) from to 99 percent by Weight inclusive of a5,5,5,4,4,3,3-heptafluoropentylsiloxane in which any remaining organicgroups attached to the silicon are methyl, in said mixture theproportions of (1) and (2) being such that there is at least .7 percentby weight (A) based on the total weight of (1) and (2).

References Cited by the Examiner UNITED STATES PATENTS 2,588,366 3/1952Dennett. 2,838,423 6/1958 Gilkey. 2,947,771 8/1960 Bailey 26029.1

OTHER REFERENCES Pierce et al., Fluorine-Containing Elastomers, WrightAir Development Center, T.R. 52-191, part 2, October 1953, page 43.

ALLAN LIEBERMA-N, Acting Primary Examiner.

LEON I. BERCOVITZ, MORRIS LIEBMAN,

Examiners.

K. B. CLARKE, I. S. WALDRON, Assistant Examiners.

1. A METHOD WHICH COMPRISES APPLYING TO AN ORGANIC FABRIC A DISPERSIONIN A LIQUID CARRIER OF (1) A SILOXANE OF THE FORMULA